Thread tensioning device



Nov. 8, 1955 w. HANSEN THREAD TENSIONING DEVICE 2 Sheets-Sheet 1 Filed Sept. 26, 1952 1 3 3 M I V/// D I,0 W

7 3 M gm m m M all/I'll H I7 INVEN TOR. WHERE/V HANSEN BY Nov. 8, 1955 w. HANSEN THREAD TENSIONING DEVICE 2 Sheets-Sheet 2 Filed Sept. 26, 1952 m m m m m i y S 5 WWW i2 #MA fi/W R United States Patent THREAD TENSIONING DEVICE Warren Hansen, East Moline, lll., assignor to Gellman Manufacturing Co., Rock Island, Ill., a corporation of Illinois This invention relates to new and useful improvements in thread tensioning devices especially adapted for use in connection with sewing machines to put tension upon the thread.

To the above ends the invention consists of the novel combination of elements hereinafter described and set forth in the claim.

A principal object of the invention is to provide a device of this character in which the thread may be placed conveniently and expediently in the tensioning device. Such an arrangement is especially desirable when it is considered that domestic sewing machines are generally operated by one other than a skilled mechanic.

Another and equally important object of the invention is to provide a thread tensioning device for a sewing machine which comprises a minimum number of parts thereby to aflord economical manufacture.

A still further object of the invention is to provide a novel and improved arrangement for adjusting the tension of the device so as to meet the requirements necessary for effective operation.

A still further object of the invention is to provide in such a tensioning device an arrangement for manually and readily relieving the tension of the device upon the thread.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

Fig. 1 is a side elevation of a portion of a sewing machine provided with my tensioning device;

Fig. 2 is a sectional detail view taken substantially on line 22 of Fig. 1;

Fig. 3 is a sectional detail view taken substantially on line 33 of Fig. 2;

Fig. 4 is a detail view of a take-up spring embodied in the invention;

Fig. 5 is a side elevational view of the same;

Fig. 6 is a face view of a housing for the take-up spring shown in Figs. 4 and 5; and

Fig. 7 is a side elevational view of the same.

In the drawings a portion of a sewing machine is indicated at 10. This sewing machine may be of any approved construction such as is disclosed in United States Letters Patent No. 2,491,622. Such sewing machine includes a head 11 having pivotally associated therewith a pressure foot lift lever 12 operable in a manner and for purpose well known in the art. I employ this lever 12 for the additional purpose of relieving the tension of the thread tensioning device constituting my invention and which will now be described.

In this connection I provide a mounting stud 13. The inner end portion of this stud 13 is fixedly secured in any suitable manner in an opening 14 formed in the wall 15 of the head 11.

15'. Threaded upon this stud 13 is a nut 16 having a I counterbore 17. Mounted on the stud 13 inwardly of the nut 16 is a housing 18 for the coiled portion of a take-up spring 19, illustrated in Figs. 4 and 5.

Between this housing 18 and the nut 16 and projecting into the counterbore 17 is an expansion spring 20 which embraces the stud 13.

A pair of confronting tension plates 21 and 22- are mounted upon the stud 13. The plate 21 is disposed in facial abutment with the wall 15 of the head 11. Such plate provides an outwardly angularly projecting finger 23-which projects through a notch 24 formed in the plate 22 thereby to provide a simple yet effective means for maintaining the plates 21 and 22 in confronting align ment with respect to each other. The. plate 22 provides a thread guide 25 in the form of a laterally extending projection. Such plate 22 is provided with an opening 26 into which projects a finger 27 provided by the housing 18. This housing 18 provides a peripheral slot 28 through which projects the spring arm 29 of the take-up spring 19. The outer end of this arm 29 is looped to provide an eyelet 30 through which the thread 31 passes for threading on the take-up lever (not shown) of the sewing machine. i

The housing 18 is provided with a plurality of concentrically arranged notches 32 in the wall 33 thereof and into these notches is adapted to be selectively projected the angled end portion 34 of the spring 19. By changing the relative position of the angled end portion 34 of the spring 19 with respect to the housing 18 the tension of the coil of such spring 19 may be varied.

The tension plates 21 and 22 are formed at their lower end portions to provide a V-shaped guiding groove 35 which facilitates the placing of the thread 31 between these plates.

The wall 15 of the head 11 has an opening 36 formed therein. In this opening 36 is slidably mounted a release pin 37. The outer end of this pin 37 is adapted to be projected through an opening 38 formed in the plate 21, into engagement with the plate 22.

A lever 39 is pivoted, as at 40, to a wall of the head I 11. This lever has an arm 41 which is adapted to bear against the pin 37. An expansion spring 42, bearing upon the wall 15 and against the lever 39 as at 43, yieldably bears the edge 44 of the lever 39 against the cam head 45 of the lift lever 12. This arrangement is such that pivotal movement of the lever 12 in a clockwise direction will pivot the lever 39 against the spring 42 to bear the pin 36 against the plate 22 and thereby move this plate a sufiicient distance away from the plate 21, against the action of the spring 20 to permit removal of the thread 31 from between the pressure plates 21 and 22.

To complete the invention a set screw 46 is threaded in the wall 15 and bears against the stud 13 to fixedly secure such stud in the opening 14. If desired the peripheral surface of the nut 16 may be knurled as at 47 to afford firmly gripping the nut 16, which not 16 may be adjusted upon the stud 13 to vary the tension between the plates 21 and 22.

From the foregoing description it is obvious that I provide a simple, effective and inexpensive thread tensioning device for a sewing machine; a device which is compact and easy of operation.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claim.

Patented Nov. 8, 1955 Having thus. described my invention. what I claim as. new and desire to protect by Letters Patent is:

A tensioning device comprising a mounting stud fixedly carried by a support, a pair 015 confronting tension plates mounted on said stud and between which a strand of thread is adapted to pass, a connection between said plates to permit axial displacement of one of said plates. with respect to the other of said. plates on. said" stud and to restrain said plates against rotation relative to each other, means engaging one of said plates to effect axial displacement of said one of said plates with respect to the other of said plates and to restrain saidother of said plates from rotation relative tosaid stud, a take-up spring having a thread engaging portion and a coiled portion: the latter embracing the stud, a housing for said coiled por tion mounted on said stud and having a portion thereof engaging said plates, said housing having a peripheral slot through which said thread engaging portion protects, means providing a detachable connection. between said heusinaand one oi. said. plates. to prevent. rotation at said housing on said stud, a nut adjustably threaded on said stud, and an expansion spring embracing said stud and arranged between said housing and said nut and bearing said housing against one of said plates for yieldably holding said plate in confronting relation with respect to the other of said plates.

References Cited in the file of this patent UNITED STATES PATENTS 756,314 Ammerman Apr. 5, 1904 994,509 Gray June 6 1911 1,534,264 Hanson Apr. 21, 1925 1,820,119 Chason Aug. 25, 1931 2,518,703 Marsac Aug. 15, 1950 FOREIGN PATENTS 414,717 Italy Aug. 24, 1946 

